A Quantitative Analysis of Drug Loading Efficiency and Real-Time Drug Release in ZrO₂ Nanoparticles with Energy Spectrum Computed Tomography.

Energy spectrum computed tomography (CT) can quantify the concentrations of substances in vitro and in vivo. In this study, we designed a single-shell system of doxorubicin (DOX) loaded in zirconium dioxide nanoparticles (DOX@ZrO₂ NPs) as a novel chemotherapy drug delivery system. The concentration of DOX@ZrO₂ NPs in tissue was monitored with energy spectrum CT to calculate the release of DOX from the NPs. The standard curve of the gradient concentrations of ZrO₂ NPs and base material content fit a logarithmic equation. HepG2 cells were incubated with 200 μmL DOX@ZrO₂ for different times. The concentration in the cells detected with energy spectrum CT correlated strongly with the concentration of chemotherapeutics in the cells (r = 0.98, P < 0.05). The data indicate that energy spectrum CT is a reliable means of real-time monitoring of the transport of NPs and release of the NP payload in local tissue. The finding could improve the accuracy of clinical imaging and promote the therapeutic use of NPs. Free of clinical trial registeration: There were no animal and human materials involved in this experiment.